The Modified Post-earthquake Damage Assessment Methodology for TCIP (TCIP-DAM-2020)

Post-Earthquake damage assessment has always been one of the major challenges that both engineers and authorities face after disastrous earthquakes all around the world. Considering the number of buildings in need of inspection and the insufficient number of qualified inspectors, the availability of a thorough, quantitative and rapidly applicable damage assessment methodology is vitally important after such events. At the beginning of the new millennia, an assessment system satisfying these needs was developed for the Turkish Catastrophe Insurance Pool (TCIP, known as DASK in Turkey) to evaluate the damages in reinforced concrete (RC) and masonry structures. Since its enforcement, this assessment method has been successfully used after several earthquakes that took place in Turkey, such as 2011 Van Earthquake, 2011 Kutahya Earthquake, 2019 Istanbul Earthquake and 2020 Elazig Earthquake to decide the future of damaged structures to be either ‘repaired’ or ‘demolished’. Throughout the years, the number of research activities focusing on the reparability of earthquake-damaged structures has increased, which is a purposeful parameter in the determination of buildings’ future after earthquakes. Accordingly, TCIP initiated a research project with a sole aim to regulate and reevaluate the damage assessment algorithm based on the results of state-of-the-art scientific research. This chapter presents the new version of the damage assessment methodology for reinforced concrete structures which was developed for TCIP (TCIP-DAM-2020). In addition, an application of the developed damage assessment algorithm on an earthquake-damaged reinforced concrete building which was struck by Kocaeli (1999) earthquake is presented.

Computer Aided Quick Determination of Earthquake Performance of Buildings by Using Street Survey and Preliminary Assessment Methods

In this study, 7 different rapid evaluation methods which are used to determine the performance of buildings under the influence of earthquakes in a fast and practical way are examined. These methods were used to determine the earthquake performance behaviors (risky or safe) of buildings according to each method by using the parameters of 50 buildings that were collapsed or severely damaged in Van earthquake that occurred in 2011. Accurate estimation percentages of the methods on the buildings were calculated by comparing the obtained earthquake performance behaviors with the current situation of the buildings. The most suitable method has been tried to determine for 50 buildings related to these calculations. At the same time, a computer program called EPA (Earthquake Performance Analysis) was developed in order to evaluate the parameters of the related data set faster, easier and without error. Three of the 7 rapid assessment methods used to determine the earthquake performance behavior of buildings are first-stage methods called street screening (6306 RYY, FEMA P-154 and Sucuoğlu and Yazgan level-1), and the remaining four methods are second-stage methods called pre-assessment (Sucuoğlu and Yazgan level-2, Özcebe, Yakut and MVP). According to the results, the pre-assessment methods predicted the earthquake performance status of the buildings examined by 24% higher than the street screening methods. At the same time, the most successful method of street survey methods was 6306 RYY with 74% accurate estimation, and the most successful method of preliminary assessment with 86% accurate prediction was Yakut method.

Monitoring potential ionospheric changes caused by the Van earthquake (<i>M</i>_w7.2)

Many scientists from different disciplines have studied earthquakes for many years. As a result of these studies, it has been proposed that some changes take place in the ionosphere layer before, during or after earthquakes, and that the ionosphere should be monitored in earthquake prediction studies. This study investigates the changes in the ionosphere created by the earthquake with a magnitude of Mw=7.2 in the northwest of Lake Erçek, which is located to the north of the province of Van in Turkey on 23 October 2011 and at 13:41 local time (−3 UT) with the epicenter of 38.75∘ N, 43.36∘ E using the TEC values obtained by the global ionosphere models (GIMs) created by IONOLAB-TEC and CODE. In order to see whether the ionospheric changes obtained by the study in question were caused by the earthquake or not, the ionospheric conditions were studied by utilizing indices providing information on solar and geomagnetic activities (F10.7 cm, Kp, Dst). One of the results of the statistical test of the TEC values obtained from both models is positive and negative anomalies obtained for the times before, on the day of and after the earthquake, and the reasons for these anomalies are discussed in detail in the last section of the study. As the ionospheric conditions on the analyzed days were highly variable, it was thought that the anomalies were caused by geomagnetic effects, solar activity and the earthquake.